1. Technical Field
The present invention relates to a unit and an image forming apparatus including it.
2. Related Art
Conventionally, in an image forming apparatus employing, for example, the electrophotographic system such as a copier, a printer, or a facsimile apparatus, in order to comply with a request for improving the operability or the maintainability, various functional members are unitized so as to constitute one unit, and the unit is replaced with another unit as required. An example of such a unit is a fixing device. An image forming apparatus using such a fixing device is configured so that a toner image which is formed in accordance with image information is transferred onto a transfer sheet, and the transfer sheet onto which the unfixed toner image is transferred is heated and pressed by the thermal fixing device to apply a fixing process, thereby fixing the unfixed toner image onto the transfer sheet to obtain a permanent image.
The fixing device is configured so as to be attachable to and detachable from the apparatus body for the purpose that, in the case where the life of the fixing device is shorter than that of the image forming apparatus, the fixing device is used as a component needing periodic replacement, and, in the case of a fault, maintenance such as replacement is performed.
In such an image forming apparatus, recently, miniaturization and reduction in weight are advancing, and, in accordance with this, also a unit is further miniaturized and reduced in weight. Therefore, a mechanism for enabling the unit to be attached to and detached from the body of the image forming apparatus is requested to attain excellent operability in addition to miniaturization and the like.
In the conventional unit, in accordance with miniaturization and weight reduction, however, an operating portion of the lock mechanism for enabling the unit to be attached to and detached from the image forming apparatus body must be made small. When the unit is to be attached to or detached from the image forming apparatus body, therefore, the user must operate the unit in the following manner. The operating portion of the lock mechanism is operated to cancel the lock mechanism. In a state where the hand is once separated from the operating portion of the lock mechanism, thereafter, another portion of the unit is held by the hand, and then the unit is attached to or detached from the image forming apparatus body. Consequently, the operability is inevitably lowered.